Patent GB-1214330-A (GB)
Title: Apparatus for making a laminated pipe cover
IPC: B29C53/60
Filed: 1968-03-07
Abstract: 1,214,330. Heat insulating coverings for pipes. BALDWIN - EHRET - HILL Inc. 7 March, 1968 [13 March, 1967], No. 11077/68. Heading F2P. Apparatus for making a laminated pipe covering, Fig. 2, comprises a transfer conveyer 26, 30, Fig. 5, for delivering at least one mat to a mandrel 50 at a wrapping station WS, actuating means for rotating the mandrel so that the mat is wrapped on the mandrel, and means for selectively varying the rotational speed of the mandrel during build up of the mat so that the peripheral speed of the mat is substantially equal to the feed speed of the transfer conveyer. As shown, a pipe cover 10, slit at 12 and partially slit at 16 to form a hinge, is formed by spirally winding an outer and every other layer Lf of a glass fibre material and intermediate layers Lm of mineral wool. Saws 24, 28, Fig. 5, having endless cutting blades, are each movable radially relative to logs 20, 22 respectively of thermosetting binder impregnated glass fibre and mineral wool, to cut mats 26, 30 of predetermined uniform thicknesses from the outer peripheries of the logs as they are rotated at two supply stations F1, F2 the mat 26 being transferred from a first 33, to a second, conveyer system 35 where the mineral wool mat 30 is superimposed upon the glass fibre mat 26. The conveyer 34 delivers the mats 26, 30, through a cut-off station C s , to the wrapping station N s  which includes a rotatably mounted mandrel assembly 50, a back-up belt assembly 52, and a stuffer mechanism 54. At the start of an operation the back-up roll assembly 52, which is in a lowered position, Fig. 23, not shown, is raised the stuffer mechanism 54 pressing the leading edges of the mats 26, 30 into engagement with the mandrel 50. After a predetermined wrapping period automatic control mechanism actuates a cut-off gate 56 at the station C s , stops the conveyers 33, 35, and, while the mandrel 50 continues to rotate at a predetermined first speed, initiates a curing cycle which includes a low flame gas burner. After a predetermined prosizing cycle the mandrel speed is increased and the gas burner is turned to a high flame for the final curing operation, the mandrel 50 then being stopped, the burner cut off, and the backup assembly 52 moved to its lower position. A stripper assembly ejects the finished pipe assembly from the mandrel and the operational cycle is automatically repeated. The two supply stations F1, F2 are identical so, considering only the station F1, the log 20 is releasably mounted on the shaft 70 and is rotatable by a continuous belt 102 mounted between curved support arms 92 which can be lowered to drive the roll 20 by hydraulic motors 123. The saw assembly 26 comprises a pair of wheels such as 110 which rotate the endless cutting blade 24 and which are mounted in housings such as 114 each of which is movable vertically by an upright jack screw 144 controlled by a microswitch unit to ensure uniform thickness of cut, limit switches S 1  S 2  controlling the extreme vertical movements of the saw assembly. The transfer conveyer (33) comprises an endless screen mesh belt 32 supported around a plurality of rolls including a drive roll 175, a driven roller 181 and a tension roller 193 loaded by counterweights 197. The conveyer system 35 is similar except that it includes a transfer link 201, 203. The cut-off blade 56, normally spring-loaded into an upper inoperative position, is actuated by an hydraulic piston and cylinder unit 211. At the wrapping station W s  the hollow mandrel 300 has a removable tailstock (310), Fig. 30, not shown, which allows a stripping mechanism (320), having a wax applicator (330), to strip a finished pipe cover from the mandrel after completion of the curing cycle. The belt 311 of the back-up assembly, driven indirectly through a motor M5, is moved vertically by a pair of jack-screws 333 which are engageable in housings 337 and which are driven by a motor M3, the belt, which is a wire mesh, being cleaned by a rotary brush cleaner 531. A back-up control linkage system (L) controls the various cycles of the apparatus such as termination of the wrapping cycle, actuation of the cutting blade assembly, and variation of the mandrel speed during the wrapping and curing cycles. The control linkage (L), Fig. 15, comprises upright linkage arms 363 which are secured to a rotatable shaft 361 and which have annularly adjustable upper links 327 connected to their opposite ends for supporting the floating roll 325. A link 369 on the shaft 361 is connected by a link 371 to a gear wheel 373 which meshes with a gear 376 of a potentiometer 379 operatively associated with the mandrel motor M2, to selectively vary the rotational speed of the mandrel in accordance with the mat build-up on the mandrel. A cam 381 on the bracket 365 engages a micro-switch S7 which controls a timing control element for the cut-off blade 56 to sever the mats when the desired amount of mat has been wrapped. A mechanism for guiding the movement of the floating roll 325 comprises a linkage 391, 395, 397 the latter arm 397 having a guide roller which engages a curved elevating cam 403. The stuffer mechanism 54, mounted on a bar 500 and including a tucker arm 504 and a pair of side thrust supports, is controlled by hydraulic actuators 508, 516 which regulated by a valve, move the mechanism radially of, and rotatably about, the bar 500. A gas burner (537), including a control circuit for initiating and regulating the flame (Fig. 28, not shown) is located under the whole length of the mandrel. A drive system for effecting the actuation of the back-up belt assemblies, the transfer conveyers, and drives for the rolls at the stations F1, F2 includes a common motor M5 and clutches 408 and 441. The machine includes a programmer Pc, consisting of a multi-cam, multi-position stepping switch control X, three timers Y, Y 1 , Y 2 , a counter mechanism Z, and control switches to control the sequence of the various operations of the machine.